Poland's deputy culture minister says he has seen a ground-penetrating radar image of the alleged Nazi treasure train that set off a gold rush, adding that he is 99 per cent sure it exists.

Local media has for days been abuzz with old lore of trains full of gold and jewels stolen by the Nazis, after two men — a German and a Pole — claimed to have found an armoured train car in the south-western city of Walbrzych.